Flue gas scrubber



M. l. DoRFAN 2,380,826

FLUE GAS SCRUBBER July 3l, 1945.

Filed Oct. 2, 1943 3 Sheets-Sheet l INVENTOR l. DORFAN July 31, 1945. M.

FLUE GAS SCRUBBER Filed Oct. 2, 1943 3 Sheets-Sheet 2 July 31, 19451 M. l. DORFAN FLUE GAS SCRUBBER Filed Oct. 2, 1943 5 Sheets-Sheet 5 INVENTOR.

Patented July si, i945 Application Dotober 2, 1943, Serial No. 504,877

6 C (Cil. 281-426) This invention relates to combination flue sas scrubbers and spark arrestare' mounted on the upper` ends of stacks, such as cupola stacks.'

where they prevent sparks from escaping into the atmosphere and wash the flue gases t remove foreign particles and noxious vapors therefrom. The invention relates more particularly to the type of scrubber in which the iiue gas spreads out laterally from the top of the stack and is washed by water falling across the outlet and through the gas from the edge of a gas deilector mounted above the stack.

It is among the obiects'of this' invention to improve upon such scrubbers to the end of causing the water to iall from the edge of the gas deilector as a substantially continuous curtain instead of in streams between which some of the gas could escape without being washed. AOther obiects are to provide a scrubber in which the iiue gas is washed a plurality of times, but which struction.

In accordance with this invention an upwardly tapered gas deilector is mounted above a stack,

from which flue gases are emerging, so that a 25 lateral outlet for the sas is formed between the edge of the deector and the top ofthe stack. A screen may extend around this outlet to prevent the escape of sparks. A verticallcasing, preferably provided with vertical corrugations, 'surrounds the deector and screen from which it is spaced. Water is delivered to the top of the deiiector and to the upper part of the inside of the casing. 'I'he water flows over the top of the tapered deilector and falls from its edge across the gas outlet, andthe water on the `casing runs down its inner surface to form a sheet of water that again washes the gas. -In order to provide a continuous curtain of water around the gas outlet, channeling of the water flowing down the de-l ector is avoided by making the deneetor polyg; onal so that its upper surface is formed from a plurality of iiat triangular surfaces sloping downwardly from its apex. 'I'he water spreads out evenly on these fiat and flows over the straight sides of the deflector in a'n unbroken curtain. The water from the deiiector and casing drains into a trough below them from which it is carried away. The water preferably is applied to the defiector and casing by a plurality of'nozllesabove the central position of the deflector, some of the poules being directed downwardly towardthedefiectorandtherestofthemspraying streams of water laterally against the surroundblessing.

The preferred embodiment of the invention is .illustrated in the accompanying drawings inv which Fig. l is a.plan view of my scrubber with the roof partly broken away; Fig. 2 is a vertical section taken on the line II- II of Fig. 1; and Figs.

l 3. 4, and 5 are enlarged fragmentary horizontal ter of the stack. is comparatively simpleand inexpensive in conf Y sections taken' on the lines III-III, IV,IV. and

'V-V, respectively, oi Fig. 2.

Referringto the drawings, a plurality oi.' metal brackets l are secured radially to the outside of a stack 2, such asa cupola, in circumferentially spaced relation near its top. Any convenient' number of brackets may be used. eight being shown in Athe drawings as the preferred number. Mounted on the outer end of each of these brackets is a column I that extends up above the top of the stack a considerable distance. The upper ends of these columns are connected by radial beams 4 to a center plate l above the cen- Within the area bounded by the columns there .ist a vertical casing formed from a plurality of metal sheets 8 that preferabh are provided with vertical corrugations to strengthen them and increase their surface area. These sheets are joined edge to edge and are supported by vertically spaced horizontal vangle irons I the ends of which Aare mounted on clip angles l, secured to the inner sides of the columns. The casing -thus is polyg- 3.0 onal horizontally, the one illustrated having eight sides. The bottom of the casing extends down along the inner surface of a continuous drain plate .U that converges downwardly toward the stack that it surrounds. The upper edge of this plate is turned outwardly'to form a flange Il that rests on clip angles Il secured to the columns. Between lplate l and the stack is anotherdrain plate i2 the upper edge of which is turned in- -wardlytoformailange Il thatissecuredtothe' v4o bottom of an angle iron." encircling the topof the stack. Inner plate l2 diverges downwardly away from the stack but does not touch the outer drain plate, whereby a drain slot Il ls formed between their lower edges. It will be observed.V

' that the drain plates, which conformto the shape of the casing, likewise are polygonal. The drain slot is located directly above a polygonal trough I8 mounted onbracketsl and also extending around the stack. The bottom ofA this trough. is

provided with openings I'I to which drain pipes Y Il are connected.

Located directly above the top of the stack and 66 iiectorisspacedaconsiderabledistaneefromthe l the same number of sides as the casing with those sides parallel to the adiacent casing sides. 'I'he deiiector is formed from a plurality of flat triangular plates 2i the bases of which form its eight straight sides and the apexes of which meet at the apex of the deilector. These flat plates have their sides turned up to form vertical anges 22 which are Joined together tp form a strong. unitary structure. The edge of the deector is turned down to provide a vertical flange 23. The defiector is supported by vertical plates 24 attached to the lower ends of its top iianges 22 and extending through slots in casing sheets t to columns 2 to which they are secured. An eight-sided `spark arresting screen 2l preferably extends from deflector flange 23 down across the gas outlet to the top of inner drain plate I2.

To wash the gases that pass from the stack out through the spark screen, water is caused to flowfrom the 'edge of the deilector down across the screen.- This water is caught by the drain plates and directed through drain slot i5 into trough I l. 'I'he water is delivered to the top of the deflector from a plurality of nozzles #Il that extend radially from a central header 3i suspended from center plate l. a pipe 22 to a suitable source of water under pressure (not shown). There is one nozzle above the upper end oi each flat plate 2| forming the deiiector, and each nozzle has two outlets. One outlet is directed down toward the defiector and the other is-directed horizontally to spray water out against the upper portions ofthe corrugated casing sheets. The water flowing down the flat deilector plates spreads out evenly, instead of- Ysheet down its. inner surface to drain plate t.

The flue gases that have passed through the curtain of water around the spark screen come in contact with the sheet of water on the casing and are subjected to further washing by it before escaping through the open top of the easing.

The open top of the casing preferably is covered by a roof Il mounted on vertical angles II secured to the upper ends of columns 2. 0f course, this roof is spaced from the casing to leave 'an outlet for the i'iue gas. l

According to the provisions of the patent stat- The header is connected by.

a,sso,sae

nector to produce a substantially continuous curtain of water falling from the edge of the deector across said outlet, and means located above the defiector for delivering water to the upper part of said casing to produce a downwardly tiow ing sheet of water on its inner surface for engagement by gas that has passed through said water curtain.

2.- A flue gas scrubber comprising an upwardly tapered polygonal gas defiector adapted to be mounted above a stack whereby to form a lateral 4nue gas outlet between the edge of the deiiector and the top of the stack, said deiiector having flat upper surfaces extending up to its apex from its several sides, a polygonal vertical casing surrounding said defiector and outlet and spaced therefrom, said casing having the same numl ber of sides as the defiector, the adjacent casing utes, I have explained the principle and construcv tion of my invention and have illustrated and described what I now consider to represent its best embodiment. However, I desire to have it understood that, within the scope of the appended claims, the invention may be practiced otherwise than as speciiically illustrated and described.

femm: i

1. A ilue gas scrubber comprising an upwardly tapered polygonal' gas deiiector adapted to be mounted above a stack whereby to form a lateral ilue gas outlet between the edge of the deilector I @said denector and outlet and spaced therefrom.

separate means for delivering water to the upper and dei'lector sides being disposed parallel to each other, separate means for delivering water to the upper portion of each of said fiat surfaces of the defiector to produce a substantially continuous curtain of water falling from the edge of the defiector across said outlet, and means located above the deiiector for delivering water to the upper part of said casing to produce a downwardly flowing sheet of water on its inner surface for engagement by gas that has passed through said water curtain.

3. A flue gas scrubber comprising an upwardly tapered polygonal gas deiiector adapted to be mounted above a stack whereby to form a lateral flue gas outlet between the edge of the deilector and the top of the stack, a spark arresting screen extending around said outlet, said defiector having fiat upper surfaces extending up to its apex from its several sides, a vertical casing surrounding said deiiector and screen and spaced therefrom, separate means for delivering water to the upper portion of each of said iiat surfaces of the denector to produce a substantially continuous curtain of water falling from the edge of the deileotor across said outlet, means for delivering water to the upper part of said casing to produce a downwardly flowing sheet of water on its inner surface for engagement by gas that has passed through said water curtain, laterally spaced drain plates converging downwardly from the lower ends of said screen and casing, and a trough below said plates for receiving water fallins therefrom.

4. A flue gas scrubber comprising an upwardly tapered polygonal gas deilector adapted to be mounted above a stack whereby to form a lateral flue gas outlet between the edge of the deilector and the top of the stack, said deflector having fiat upper surfaces extending up to its apex from its several sides, a vertical casing surrounding said deilector and outlet and spaced therefrom, said casing being provided with vertical corrugations, separate means for delivering water to the upper portion of each of said flat surfaces of the defiector to produce a substantially continuous curtain of water falling from the edge yof the deilector across said outlet, and means for delivering water to the upper part of said casing to produce a downwardly flowing sheet of water on its inner surface for' engagement by gas that has passed through said water curtain.

5. A flue gas scrubber comprising an upwardly tapered polygonal gas defiector adapted to be mounted above a stack whereby to form a lateral 'ilus gas outlet between the edge of the deflector and the top of the stack, said deiiector having portion of each of'said nat surfaces of thelde- 75 `fiat upper surfaces extending up toits apex from its severa-1 sides, a vertical casing surrounding said deflector and outlet and spaced therefrom, downwardly directed jets above the deflector for spraying water on top of the delector to produce a substantially continuous curtain of water falling from the edge of the deilector across said outlet, one of sad jets being directed against the upper portion of each of said flat surfaces, and laterally directed jets above the deilector for spraying water on the upper part of the inner surface of the casing to produce a downwardly flowing sheet of water for engagement by gas that has passed through said water curtain.

6. A flue gas scrubber comprising an upwardly tapered polygonal gas deector adapted to be mounted above a stack whereby to form a lateral flue gas outlet between the edge o1' the de- 15 casing.

flector and the top of the stack, said deflector having flat upper surfaces extending up to its apex from its several sides, a vertical casing surrounding said detlector and outlet and spaced therefrom, a header mounted above the center of said deflector, means for supplying water under pressure to said header, and a plurality of nozzles projecting radially from the header with a separate nozzle disposed above the upper portion of each of said flat surfaces, each nozzle being provided with an outlet in its bottom for spraying water on the underlying nat surface and with an outlet in its outer end for spraying water on` the upper part of the inner surface of the 

